scholarly journals Pulsed magnetic flux leakage method for hairline crack detection and characterization

AIP Advances ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 047207 ◽  
Author(s):  
Chukwunonso K. Okolo ◽  
Turgut Meydan
Keyword(s):  
Magnetic Flux ◽  
Crack Detection ◽  
Magnetic Flux Leakage ◽  
Flux Leakage

scholarly journals Investigation of and Components of the Magnetic Flux Leakage in Ferromagnetic Laminated Sample

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mustafa Göktepe
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Crack Detection ◽  
Industrial Applications ◽  
Magnetic Flux Leakage ◽  
Longitudinal Magnetization ◽  
Flux Lines ◽  
Power Stations ◽  
Leakage Field ◽  
Flux Leakage

The magnetic flux leakage (MFL) technique is most commonly used for crack detection from iron bars, laminated sheets, and steel tubes of ferromagnetic nature. Magnetic flux leakage system induces a magnetic field and detects magnetic flux lines that “leak” or change because of a discontinuity in the magnetized area. An inductive coil sensor or a Hall effect sensor detects the leakage. Magnetic methods of nondestructive testing (NDT) depend on detecting this magnetic flux leakage field. The ferromagnetic specimen is magnetized by suitable methods, and flaws which break the surface or just the subsurface distort the magnetic field, causing local flux leakage fields. It is very important for industrial applications to detect cracks and flaws in metal parts of the steel bridges, power stations, military tools and structures, and so forth. In this study, the inspection of cracks in laminated sheets under longitudinal magnetization will be discussed in detail.

Integration of Multiple ILI Technologies for Robust Understanding of Unique Anomalies on a Pipeline

2020 ◽  
Author(s):  
Taylor Shie ◽  
Andrew Lutz ◽  
Paul Taverna
Keyword(s):  
Magnetic Flux ◽  
Crack Detection ◽  
Low Frequency ◽  
Management Program ◽  
Probability Of Detection ◽  
Magnetic Flux Leakage ◽  
Electric Resistance ◽  
Seamless Pipe ◽  
Integrity Management ◽  
Flux Leakage

Abstract Pipeline operators have many choices when selecting inline inspection (ILI) vendors and technologies. No single technology has a one hundred percent probability of detection, identification, and sizing for all anomaly types. Operators must match the threats on their system to the existing capabilities of the ILI technologies to achieve the goals defined by the company’s integrity management program. It is sometimes necessary to run multiple technologies to effectively assess all threats in a pipeline. Multiple technologies may be run during the same timeframe or they may be run at different times during the life of the pipeline to meet program goals. Shell Pipeline Company, LP (SPLC) has a pipeline that is comprised of low frequency electric resistance welded (LFERW) pipe from Youngstown Sheet and Tube, seamless pipe from National Tube, double submerged arc welded (DSAW) pipe from Kaiser, and high frequency electric resistance welded (HF-ERW) pipe. The LF-ERW pipe was installed in 1948 while the HF-ERW was installed during relatively recent replacement projects. The DSAW pipe was installed in 1952 with the seamless pipe being installed in both 1948 and 1952. From 2015 through 2018, SPLC executed an extensive integrity management program. This included: an axial magnetic flux leakage (AMFL) inspection, two circumferential magnetic flux leakage (CMFL) inspections, two deformation inspections, an electro-magnetic acoustic transducer (EMAT) inspection, an ultrasonic crack detection (UTCD) inspection, an ultrasonic wall measurement (UTWM) inspection, and a hydrotest. A dig campaign of nearly 100 excavations was completed as a result of these surveys. One of the focuses of the paper will be the comparison of EMAT to UTCD for Likely Cracks, Possible Cracks and Unlikely Cracks that have been field verified. This paper also shares some of the unique anomalies found through the dig campaign identifying the effectiveness of each technology and their combination for integrity purposes. The paper shows the benefits of combining ILI technologies to properly characterize, assess and mitigate reported anomalies and ensure there are no blind spots in the integrity management program. Case studies including dent with gouge (e.g. AMFL + Deformation), manufacturing, and cracking anomalies as well as the analytics of ILI versus field findings are presented and discussed in the paper. The paper concludes with the knowledge creation resulting from multiple ILI technology integration assisted with subject matter expert experience and analytics to provide a robust understanding of unique anomalies in pipelines.

Pulsed magnetic flux leakage techniques for crack detection and characterisation

2006 ◽  
Vol 125 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Ali Sophian ◽  
Gui Yun Tian ◽  
Sofiane Zairi
Keyword(s):  
Magnetic Flux ◽  
Crack Detection ◽  
Magnetic Flux Leakage ◽  
Flux Leakage
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